Mars Express Bistatic Radar Experiment Operations Plan and Report 10-11 April 2005 Summary ======= DSN Antenna: 43 Pass: 680 Orbit: 1583 Orbit Start Time: 2005-04-10T21:06:02 HGA Pointing: Inertial Specular Condition (ERT): 23:38 Target Latitude (deg N): -45.25 Longitude (deg E): 63.70 Rp (km): 3380.298 Incidence/Reflection Angle (deg): 51.88 Slant Range (km): 5940 Slew Angle (deg): 76.24 Doppler (carrier, fd; Hz): -26525 Doppler (echo, fr; Hz): 26943 Doppler Difference (fdd; Hz): -53468 Earth-Mars Distance (m): 2.285E+11 Data Acquisition ================ The experiment was supported by DSS 43 staff at the Canberra DSN complex. The support team at JPL included Gene Goltz, Danny Kahan, Sami Asmar, and Dick Simpson. In the NOPE area were Jose Valencia and Jesse Velasco. The experiment began with pre-calibration activities starting on 10 April at 19:05; the pre-cal was completed an hour ahead of schedule. The bistatic surface observations were collected in the interval 23:08-23:56, but echoes were seen during only about 15 minutes centered on 22:37. The post- calibration was started after completion of the second Mini-Calibration completed and the RSR's stopped recording at 00:57 on 11 April. Valencia had slightly improved the calibration procedure and briefing message compared with the version which had been used in the previous experiment on 02-03 April. There were only minor problems, mostly resulting from the fact that it is difficult to see the effect of 6-9K S-band noise diodes against an ambient load background. This may be addressed by using the MFQ=ON option in configuring the noise diodes and by obtaining more precision in the RSR display of ADC RMS. RSRs were configured as follows. Table 1 -------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- -------- RSR1A S-LCP 1-W auto 60 Kahan RSR1B X-LCP 1-W auto 60 Kahan RSR2A S-RCP 1-W auto 60 Goltz RSR2B X-RCP 1-W auto 60 Goltz Subchannels were defined as follows: Table 2 ---------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 1 ksps Used for seeking weak carrier signals 2 8 ksps 3 25 ksps Primary recording bandwidth 4 100 ksps Backup recording (able to capture both X-band residual carrier and surface echo) Predicts were provided by NSS and were for one-way operation. Table 3 lists ADC RMS levels read from RSR displays during the experiment; most of these were collected by Gene Goltz. Times are in UTC and may not reflect actual time when configurations changed. For more accurate times, see the section of this report on Amplitude Calibration. Acronyms and abbreviations are explained below Table 3. Table 3 ----------------------------------------------------------------------------- TIME (ERT) RSR1A RSR1B RSR2A RSR2B COMMENTS 2005-04-10 S-LCP X-LCP S-RCP X-RCP RMS RMS RMS RMS ---------- ----- ----- ----- ----- ----------------------------------------- 18:45 Voice net established (MEX MOC, MEX NOPE, DSS 43, and RSSG) 19:35 DSS 43 reports AMB physical temperatures: S1=19.44 S2=21.31 X1=21.12 Weather: sky overcast; rain 2 hrs before T=16.78C P=947.06 19:40 28 29 29 29 All channels to sky; RSR attenuators set by AUTO 19:42 28 88 29 89 X-band to AMB 19:43 84 88 29 89 S-LCP to AMB 19:44 84 88 88 89 S-RCP to AMB 19:47 29 30 29 29 Reset RSR attenuators using AUTO; all RSR's to AMB; begin all RSR recording (subchannel 3) 19:48 29 30 30 30 X-RCP ND ON 19:53 29 7 30 12 X-band to sky (X-RCP ND still ON) 19:58 30 7 30 7 X-RCP ND OFF 20:03 30 11 30 7 X-LCP ND ON 20:08 29 30 30 28 X-band to AMB (X-LCP ND still ON); DSS 43 reports AMB physical temperatures: S1=19.44 S2=21.31 X1=21.06 20:13 29 29 30 28 X-LCP ND OFF 20:18 29 7 30 7 X-band to sky 20:23 29 7 30 7 S-RCP ND ON 20:28 29 7 9 7 S-RCP to sky (S-RCP ND still ON) 20:33 29 7 8 7 S-RCP ND OFF (DSS confirmed 12.5K value) 20:38 30 7 8 7 S-LCP ND ON 20:43 9 7 8 7 S-LCP to sky (S-LCP ND still ON) 20:48 8 7 8 7 S-LCP ND OFF 20:53 8 7 9 7 S-RCP ND ON (reconfirmation) 20:58 8 7 8 7 S-RCP ND OFF (reconfirmation); DSS 43 reports AMB physical temperatures: S1=19.44 S2=21.38 X1=21.00 21:03 End all RSR recording 22:01 S-RCP carrier SNR=46 dB; X-RCP SNR=57 dB 22:05 BOT; DSS 43 confirms X/3-W carrier lock; Begin all RSR recording (subchannel 3) 22:09:37 TLM OFF; X-RCP SNR=69 dB, f=-21074 Hz; S-RCP SNR=46 dB, f=-6300 Hz; X-LCP SNR=20 dB; S-LCP SNR=21 dB 22:10 DSS 43 reports S/3-W carrier lock after resolving Franz code error) 22:15:46 AOS 1-way; X-RCP SNR=69 dB, f=-2751 Hz; S-RCP SNR=46 dB, f=-1297 Hz 22:38 8 7 8 7 Enter X FRO=45000; X-RCP f=-47908 Hz; Enter S FRO=6000; S-RCP f=-7337 Hz 22:41:58 Begin Slew #1 to BSR attitude 22:44 8 7 8 7 All to sky; Begin Mini-Calibration #1 22:45 8 7 8 11 X-RCP ND ON 22:48 8 7 9 7 X-RCP ND OFF; S-RCP ND ON 22:51 8 11 8 7 S-RCP ND OFF; X-LCP ND ON 22:54 9 7 8 7 X-LCP ND OFF; S-LCP ND ON 22:57 8 7 8 7 S-LCP ND OFF; End Mini-Calibration #1 23:06:28 End Slew #1 23:10 Begin RSR recording (subchannel 4) 23:32 Convincing X-LCP echo at f=2500 Hz 23:37 X-LCP SNR=29 dB, X-RCP SNR=26, f=5600 Hz 23:40 X-LCP SNR=19 dB, f=7500 Hz 23:42 X-LCP f=9300 (close to edge, intermittent) 23:55 Stop RSR recording subchannel 4; 8 7 8 7 Begin Mini-Calibration 23:56:48 Begin Slew #2 back to Earth; X-TX OFF, S-TX OFF 23:58 Begin Mini-Calibration #2 23:58 8 7 8 11 X-RCP ND ON 00:01 8 7 9 7 X-RCP ND OFF; S-RCP ND ON 00:04 8 11 8 7 S-RCP ND OFF; X-LCP ND ON 00:07 10 7 8 7 X-LCP ND OFF; S-LCP ND ON 00:10 8 7 8 7 S-LCP ND OFF; End Mini-Calibration #2 00:12:20 Spacecraft enters eclipse 00:21:48 End Slew #2 00:25 29 30 30 29 All Channels to AMB. DSS 43 reports AMB physical temperatures: S1=19.75 S2=21.38 X1=21.81 00:30 29 30 30 30 X-RCP ND ON 00:33 30 29 30 28 X-RCP ND OFF; S-RCP ND ON 00.36 30 31 29 28 S-RCP ND OFF; X-LCP ND ON 00:39 30 30 30 28 X-LCP ND OFF; S-LCP ND ON 00:42 9 7 8 7 All to sky (S-LCP ND still ON) 00:45 8 10 8 7 S-LCP ND OFF; X-LCP ND ON 00:48 8 7 9 7 X-LCP ND OFF; S-RCP ND ON 00:51 8 7 8 11 S-RCP ND OFF; X-RCP ND ON 00:54 8 7 8 7 X-RCP ND OFF 00:57 Stop RSR recording. DSS 43 reports AMB physical temparatures: S1=19.88 S2=20.44 X1=20.88 Weather: light cloud cover T=24C H=53 percent AMB = ambient load BOT = Beginning of Track CONSCAN = conical scan tracking EOT = End of Track FRO = frequency offset HGA = high-gain antenna LOS = loss of signal ND = noise diode No = noise power Pc = carrier power S1 = ambient load for S-RCP S2 = ambient load for S-LCP SL = S-LCP SR = S-RCP TLM = telemetry X1 = Ambient load for both X-band channels XL = X-LCP XR = X-RCP original: 2005-04-28 added summary section, minor edits: 2006-05-04